How does a gastric band work?
The American Society for Metabolic and Bariatric Surgery (ASMBS) estimates that around 216,000 bariatric surgeries were performed in the U.S. in 2016. Of these, 3.4 percent were gastric bands. Gastric sleeve surgery was the most common type, accounting for 58.1 percent of procedures.
Here are some key points about gastric band surgery.
- Gastric band surgery is a type of weight loss, or bariatric, surgery.
- It is a minimally invasive, quick, reversible and adjustable surgical procedure that decreases the size of the stomach to reduce food intake.
- It involves placing an inflatable band around the top of the stomach, which results in a person feels fuller with less food.
- After surgery, it is necessary to follow a strict liquids-only diet with gradual reintroduction of soft foods for up to 6 weeks.
- Banding can result in significant weight loss and improve diabetes, but weight loss varies greatly.
How does it work?
Gastric band surgery involves applying an inflatable band to reduce the size of the stomach.
Gastric banding is a type of weight-loss surgery that involves placing a silicone band around the upper part of the stomach to decrease stomach size and reduce food intake.
It is approved for use as a weight-loss treatment by the U.S. Food and Drug Administration (FDA).
The band is placed around the upper portion of the stomach, and the tube attached to the band is accessible through a port under the skin of abdomen.
Using this port, the surgeon injects saline solution into the band to inflate it.
Adjustments are made to alter the degree of constriction around the stomach. The band creates a small stomach pouch above it, with the rest of the stomach below.
The smaller stomach pouch reduces the amount of food that can be held in the stomach at any one time. The result is an increased feeling of fullness after eating a smaller amount of food. This, in turn, reduces hunger and helps lower overall food intake.
An advantage of this form of bariatric procedure is that all food consumed is digested and absorbed normally. There is no malabsorption.
A gastric band is fitted under general anesthesia. It is usually done in an outpatient clinic, and the individual usually goes later the same day.
The procedure is minimally invasive. It is performed through keyhole incisions. The surgeon makes between one and five small surgical cuts in the abdomen. Surgery is carried out using a laparoscope, a long narrow tube with a camera. The procedure often takes 30 to 60 minutes.
The patient should not eat from midnight before the day of the surgery. Most people can resume most normal activities within 2 days, but they may need to take a week's leave from work.
Diet after surgery
At first, the intake of food must be restricted.
- For the first few days, diet is restricted to water and fluids, such as thin soups.
- Until the end of 4 weeks, liquids and blended foods, such as yogurt and puréed vegetables can be eaten.
- From 4 to 6 weeks, soft foods are introduced.
- After 6 weeks, the person can resume a normal diet.
Who should have it?
Gastric band placement is only recommended in cases of severe obesity, when the body-mass index (BMI) is 35 or above, or over 30 if there are other obesity-related problems, such as diabetes, hypertension, or sleep apnea.
Surgery is only considered after other forms of treatment have failed, such as lifestyle changes to diet and activity, and medications.
Weight loss surgery is not recommended for people with:
- current drug or alcohol abuse
- uncontrolled psychiatric illness
- impaired ability to understand the risks and benefits, outcomes, alternatives, and lifestyle changes demanded
The advantages of laparoscopic gastric banding include:
- the possibility of long-term weight loss for those with obesity
- relatively rapid recovery
- smaller chance of wound infections and hernias after surgery
- reduced risk of diabetes, high blood pressure, urinary incontinence, and other conditions related to excess weight
- no loss of nutrient absorption
- improved quality of life after surgery in many cases
There is also the option to remove or adjust the band. Adjustability means it can be tightened or loosened, for example, if not enough weight is being lost, or there is vomiting after eating.
On average, between 40 and 60 percent of excess weight may be lost, but this depends on the individual.
There are some risks associated with having a gastric band.
These include the following:
- Some people have an adverse reaction to anesthesia, including allergic reactions, breathing problems, blood clots in the legs that may travel to the lungs (pulmonary embolism), blood loss, infection, and heart attack or stroke during or after surgery.
- Weight loss may be slower compared with other types of surgery
- The band can slip or have mechanical problems, or it may erode into the stomach, requiring removal.
- The port can shift, making additional surgery necessary. Between 15 and 60 percent of people are reported to need follow-up surgery.
The individual needs to follow dietary recommendations with care, as overeating can lead to vomiting or dilation of the esophagus
As with other types of weight loss surgery, gastric banding also carries these risks:
- injury during surgery to the stomach, intestines or other abdominal organs
- inflammation of the stomach lining (gastritis), heartburn, and stomach ulcers
- wound infection
- gastrointestinal scarring that can lead to bowel blockage
- poorer nutrition as a result of the restricted food intake
Weight loss can give some people a boost in confidence, and this can be another benefit.
However, if a person undergoes the procedure in the hope of sudden weight loss, or if weight loss is their main reason for choosing surgery, they may be disappointed.
Diagram of surgical options.
Image source: The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
The gastric band is not the only form of bariatric surgery.
Gastric bypass: Also known as Roux-en-Y (RNY) gastric bypass.
In this procedure, the surgeon staples the stomach to make it smaller, then attaches the stomach directly into the small intestine. This reduces food intake and absorption of calories and other nutrients.
Disadvantages include the fact that it changes the gut hormones and reduces nutrient absorption. It is also difficult to reverse.
Sleeve gastrectomy: This involves removing a large portion of the stomach and leaving a tube or banana-shaped sleeve that is closed with staples. This reduces the amount of food needed to feel full, but it can also disrupt metabolism. It is not reversible.
The video below, produced by Sutter Health, shows what happens to the gut during a sleeve gastrectomy.
Duodenal switch: Surgery involves two procedures. First, the surgeon redirects the food to the small intestine, as in gastric sleeve surgery. Next, the food is further redirected to bypass most of the small intestine. Weight loss is more rapid, but the risks are greater, including surgery-related problems and nutritional deficits.